U.S. patent number 4,988,504 [Application Number 07/087,051] was granted by the patent office on 1991-01-29 for silicone surfactants.
This patent grant is currently assigned to General Electric Company. Invention is credited to William J. Raleigh, Raymond J. Thimineur, Anthony A. Zotto.
United States Patent |
4,988,504 |
Zotto , et al. |
January 29, 1991 |
**Please see images for:
( Certificate of Correction ) ** |
Silicone surfactants
Abstract
Certain polysiloxane surface active agents containing radial
organic polyether groups provide for improved stability of silicone
emulsions, particularly antiperspirant stick compositions.
Inventors: |
Zotto; Anthony A. (Troy,
NY), Thimineur; Raymond J. (Scotia, NY), Raleigh; William
J. (Rensselaer, NY) |
Assignee: |
General Electric Company
(Waterford, NY)
|
Family
ID: |
22202831 |
Appl.
No.: |
07/087,051 |
Filed: |
August 19, 1987 |
Current U.S.
Class: |
424/65; 556/439;
514/63; 556/445 |
Current CPC
Class: |
A61K
8/0229 (20130101); A61Q 15/00 (20130101); A61K
8/891 (20130101); C08G 77/46 (20130101) |
Current International
Class: |
C08G
77/00 (20060101); C08G 77/46 (20060101); A61K
007/32 () |
Field of
Search: |
;424/68,65,66,67 ;514/63
;556/445,423,439 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Sneed; H. M. S.
Assistant Examiner: Saba; J.
Claims
What is claimed is:
1. A polysiloxane surface active agent comprising:
(a) units of the formula
where R is hydrogen or a substituted or unsubstituted hydrocarbon
radical of from 1 to 12 carbon atoms;
(b) units of the formula:
where R.sup.1 is a polyalkylene ether of the formula:
where R.sup.2 is --CH.sub.2 CH.sub.2 --, R.sup.3 is a substituted
or unsubstituted alkylene group of 1 to 20 carbon atoms, R.sup.4 is
the same as R, n has a value of from 5 to about 20, and "a" is 0 or
1; and
(c) endcapping units;
with the proviso that the polysiloxane absent R.sup.1 has a
molecular weight of from about 25,000 to about 35,000 and the
weight ratio of R.sup.1 to polysiloxane absent R.sup.1 is from
greater than 15/85 to less than 35/65.
2. The polysiloxane surface active agent of claim 1 wherein about
80% by number of R is methyl.
3. The polysiloxane surface active agent of claim 1 wherein n has a
value of from about 10 to about 15.
4. The polysiloxane surface active agent of claim 1 wherein R.sup.1
has a maximum weight of less than about 900.
5. The polysiloxane surface active agent of claim 3 wherein R.sup.1
has a molecular weight of about 700.
6. The polysiloxane surface active agent of claim 1 wherein R.sup.3
is derived from a compound selected from the group consisting of
alpha-beta unsaturated carboxylic acids and alpha-beta unsaturated
alcohols.
7. The polysiloxane surface active agent of claim 1 wherein R.sup.3
is selected from the group consisting of --CH.sub.2 CH.sub.2
CH.sub.2 --, --CH.sub.2 CH.sub.2 --, --CH.sub.2 CH.sub.2 CH.sub.2
CH.sub.2 --, and --(CH.sub.2).sub.10 (C.dbd.O)--.
8. The polysiloxane surface active agent of claim 1 wherein the
weight ratio of R.sup.1 to polysiloxane absent R.sup.1 ranges from
about 20/80 to about 30/70.
9. The polysiloxane surface active agent of claim 1 wherein the
ratio of (b) units to all other siloxane units is greater than
about 10/400.
10. The polysiloxane surface active agent of claim 1 wherein the
ratio of (b) units to all other siloxane units is greater than
about 15/400.
11. An antiperspirant stick composition comprising:
(A) from about 100 to 200 parts by weight of water having an active
ingredient dissolved therein; in a discontinuous phase in about 100
parts by weight of a continuous oil matrix containing:
(B) about 50 to 75% by weight cyclic polysiloxane fluid;
(C) about 25 to 50% by weight of an organic wax; and
(D) about 0.25 to 5% by weight of a polysiloxane surface active
agent comprising:
(a) units of the formula:
where R is hydrogen or a substituted or unsubstituted hydrocarbon
radical of from 1 to 12 carbon atoms;
(b) units of the formula:
where R.sup.1 is a polyalkylene ether of the formula:
where R.sup.2 is a --CH.sub.2 --CH.sub.2 -- group, R.sup.3 is a
substituted or unsubstituted alkylene group of 1 to 20 carbon
atoms, R.sup.4 is the same as R, n has a value of from 5 to about
20, and "a" is 0 or 1; and
(c) endcapping units;
with the proviso that the polysiloxane absent R.sup.1 has a
molecular weight of from about 25,000 to about 35,000 and the
weight ratio of R.sup.1 to polysiloxane absent R.sup.1 is from
greater than 15/85 to less than 35/65.
12. The stick composition of claim 11 wherein said polysiloxane
surface active agent has an R.sup.2 of 100% by number --CH.sub.2
CH.sub.2 --.
13. The stick composition of claim 11 wherein said polysiloxane
surface active agent has an n with a value of from 10 to about
15.
14. The stick composition of claim 11 wherein said polysiloxane
surface active agent has a weight ratio of R.sup.1 to polysiloxane
absent R.sup.1 of from about 20/80 to about 30/70.
15. The stick composition of claim 11 wherein said polysiloxane
surface active agent has a ratio of (b) units to all other siloxane
units greater than about 10/400.
16. The stick composition of claim 11 wherein said organic wax is a
mixture comprising from 50 to 90% by weight solid alkanol.
17. The stick composition of claim 11 wherein said active
ingredient is an aluminum salt for antiperspirant effect.
18. The stick composition of claim 11 wherein said cyclic
polysiloxane fluid boils between about 175.degree. and 250.degree.
C.
19. The stick composition of claim 11 wherein said organic wax has
a melting point between about 40.degree. and 65.degree. C.
20. The stick composition of claim 11 wherein R.sup.3 is derived
from a compound selected from the group consisting of alpha-beta
unsaturated carboxylic acids and alpha-beta unsaturated alcohols.
Description
The present invention relates to surface active agents of
polysiloxane. More particularly, the present invention relates to
polysiloxane surface active agents having radial organic polyether
groups for use in stabilizing silicone emulsions.
BACKGROUND OF THE INVENTION
The use of polysiloxane surface active agents containing radial
organic polyether groups to stabilize silicone emulsions is well
known. U.S. Pat. No. 4,265,878 uses a polysiloxane surface active
agent to stabilize antiperspirant stick compositions. U.S. Pat. No.
4,218,250 uses such a polysiloxane surface active agent to
stabilize polish formulations. U.S.
No. 4,268,499 uses these surface active agents to stabilize
antiperspirant emulsion compositions. Further, U.S. Pat. No.
4,311,695 uses such surface active agents in personal care creams
and the like.
The subject Polysiloxane surface active agents are generically
known and are sometimes referred to as siloxane-oxyalkylene
copolymers. However, their use to date as stabilizers for silicone
emulsions has not been completely satisfactory because the
variables effecting their function are not well understood.
It is the object of the present invention to produce novel
polysiloxane surface active agents containing radial organic
polyether groups.
It is another object of the present invention to produce such
polysiloxane surface active agents for polishes, sun screen oils,
antiperspirant lotions, body lotions, and particularly for improved
antiperspirant stick compositions.
It is another object of the present invention to produce such
polysiloxane surface active agents for antiperspirant stick
compositions having improved stability, remelt stability, and low
wax content.
SUMMARY OF THE INVENTION
Briefly, there is provided by the present invention a surface
active agent of polysiloxane comprising (a) units of the
formula:
where R is hydrogen or a substituted or unsubstituted hydrocarbon
radical of from 1 to about 12 carbon atoms and (b) units of the
formula
where R.sup.1 is a polyalkylene ether of the formula:
where R.sup.2 is a --CH.sub.2 --CH.sub.2 --group, R.sup.3 is a
substituted or unsubstituted alkylene group of from 1 to 20 carbon
atoms, R.sup.4 is the same as R, n has a value of from about 5 to
about 20, and "a" is 0 or 1, with the proviso that the polysiloxane
absent R.sup.1 has a molecular weight of from about 10,000 to about
40,000 and the weight ratio of R.sup.1 to polysiloxane absent
R.sup.1 is from greater than 15/85 to less than 35/65. These
surface active agents may be combined with water, cyclic
polysiloxane fluid, organic waxes and active ingredient, to produce
antiperspirant sticks of improved properties.
In addition to the (a) and (b) units described above, the
polysiloxane surface active agent may also include (c) units of the
formula
and will of course include end capping units which are preferably
R.sub.3 SiO.sub.1/2 but may have one or more of the R groups
replaced with R.sup.1, hydroxy or alkoxy. The use of the units of
(c) is not preferred and where used, they should constitute from
about 0.1 to about 1% by number of siloxane units.
Suitable R groups include hydrogen, methyl, ethyl, vinyl, phenyl,
trifluoropropyl, etc. Preferably, at least about 80% by number of
all R groups are methyl.
R.sup.2 may be --CH.sub.2 CH.sub.2 --, --CH.sub.2 CH(CH.sub.3)--,
--CH.sub.2 C(CH.sub.3)2--, --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2
--, etc. However, it is preferred and even necessary to form
emulsions herein that at least 50% by number of R.sup.2 be
--CH.sub.2 CH.sub.2 --. Most preferably, all of the R.sup.2 units
are --CH.sub.2 CH.sub.2 --.
It is critical herein that the number of repeating units of
R.sup.1, i.e. the value of n be between about 5 and 20. Thus, in
the case of ethylene oxide as the repeating unit, the molecular
weight of R.sup.1 should be less than about 900. The preferred
value of n is from 10 to 15, which likewise for ethylene oxide
provides a molecular weight for R.sup.1 of no more than about
700.
R.sup.3 is the group which bonds the polyoxyalkylene segment to the
polysiloxane. Preferably, this group is derived from alpha-beta
unsaturated carboxylic acids or alcohols. Thus,
R.sup.3 may be --CH.sub.2 CH.sub.2 CH.sub.2 --, --CH.sub.2 CH.sub.2
--, --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 --, --(CH.sub.2).sub.10
(C=0)-- etc. Preferably, R.sup.3 is --CH.sub.2 CH.sub.2 CH.sub.2
--. Otherwise, "a" could be 0 and the segments joined by --O--
which is the product of a condensation reaction between a
condensable substituent on the polysiloxane and a condensable end
group on polyalkylene oxide.
R.sup.4 is the terminal group of the polyalkylene ether. The type
of R.sup.4 is not critical and may be selected from hydrogen,
methyl, ethyl, propyl, butyl, phenyl, alkenyl, acetyl, etc.
Preferably, R.sup.4 is hydrogen.
The polysiloxane absent R.sup.1 should have a molecular weight
between about 10,000 and 40,000 and preferably between 25,000 and
35,000. Further, the weight ratio of R.sup.1 to polysiloxane absent
R.sup.1 should range from greater than 15/85 to less than 35/65 on
a weight basis. Preferably, this ratio is between about 20/80 to
30/70. Given this ratio and a value for n above, it is possible to
calculate the ratio of (b) siloxane units to all other siloxane
units for any given surfactant. It is preferred herein that this
ratio be greater than about 10/400 and preferably greater than
about 15/400. The upper limit of this ratio is not as important and
can be generally determined from ratios already given.
The polysiloxane surface active agent may be prepared by well known
methods. The preferred method is to introduce an alpha-beta
unsaturated alcohol or carboxylic acid into the polymerization of
alkylene glycols to produce a terminally unsaturated polyalkylene
oxide. These terminally unsaturated polyalkylene glycols are
subsequently added to silicon bonded hydrogens on suitable
polysiloxanes. The addition reaction proceeds best in the presence
of an active metal catalyst such as platinum.
The manufacture of the polysiloxane surface active agents is well
known and understood. Methods of preparation are taught in U.S.
Pat. Nos. 4,265,878; Re 25,727; 3,174,987; 4,122,029; 3,172,899,
and hereby incorporated by reference.
Antiperspirant stick compositions having improved properties may be
formulated using the polysiloxane surface active agent. Such
compositions contain (A) from about 100 to 200 parts by weight
water having the desired amount of active ingredient dissolved
therein as a discontinuous phase in about 100 parts by weight of a
continuous oil matrix containing (B) about 50 to 75% by weight
cyclic polysiloxane fluid, (C) about 25 to 50% by weight of an
organic wax, and (D) about 0.25 to 5% by weight of polysiloxane
surface active agent.
The active ingredient may be an aluminum salt for antiperspirant
effect, a perfume, a dye, etc., so long as it is soluble or
dispersible in water or oil. Preferably, there should be no more
than about 1 part by weight active ingredient dissolved or
dispersed in each 1 part by weight of water.
Cyclic polysiloxane fluid for use herein is a fluid of the formula
##STR1## where b is 3, 4, 5, 6 or 7 and R is given above. It is
important herein that the fluid evaporate from the skin at a rate
which is slow enough not to make evaporative cooling noticeable but
which is rapid enough that the skin quickly feels dry. Thus R and b
should be chosen such that the boiling point of the cyclic
polysiloxane fluid or blend of fluids is between about 175.degree.
and 250.degree. C. Preferred polysiloxanes are
octamethylcyclotetrapolysiloxane and
decamethylcyclopentapolysiloxane.
Suitable organic waxes include mineral waxes, such as paraffin,
etc; vegetable waxes, such as carnauba, flax, candelilla, etc.; and
animal waxes such as bees wax. Chemically these waxes are branched
or straight chain hydrocarbons, high molecular weight fatty acid,
high molecular weight alcohols, or high molecular weight fatty acid
esters. Characteristically waxes have low viscosities just above
their melting point. For use herein the waxes should have a melting
point between about 40.degree. and 65.degree. C. Such a melting
point allows for proper application rates and prevents melting upon
storage under ambient conditions. Preferably the organic wax is a
mixture of waxes to control the hardness of the stick composition.
Thus, a preferred organic wax is a mixture of a waxy ester for
hardness, such as methyl hydroxystearate, and a solid alkanol such
as stearyl alcohol. Where such a mixture of waxes is used, the
organic wax might contain 10 to 50% by weight solid alkanol and 50
to 90% by weight waxy ester. Hardness is also greatly effected by
the proportion of organic wax in the stick composition. Preferably,
the continuous oil matrix contains about 25 to 40% by weight
organic wax.
The antiperspirant stick is easily prepared by methods well known
in the art. Herein the cyclic polysiloxane, organic wax, and
polysiloxane surface active agent are heated until all components
are liquid and then mixed. Generally the components will liquify
between about 40 and 70.degree. C. Subsequently the water solution
with active ingredient is warmed and emulsified into the molten wax
as is known. The warm emulsion is poured as close to solidification
temperature as possible into molds and allowed to cool. The solid
stick compositions containing the polysiloxane surface active agent
described herein have improved stability and are drier than
described in the prior art.
Other surfactants and additives may be included in the stick
composition as experience has taught to be beneficial for specific
formulations. For example, talc may be added to the oil phase and
incorporated into the stick composition. Further, it may be known
that further surfactants are beneficial to certain formulations,
i.e. surfactants such as polyalkylene ethers, diglycerides,
sorbitan monopalmitate, polyoxyethylene (20) sorbitan trioleate,
complex fatty acid condensate, etc. The required or proper amount
is well known to persons skilled in the art. The following examples
are offered by way of illustration and not by way of limitation.
All parts are in parts by weight.
SURFACTANTS 1 to 6
These examples illustrate the production of different polysiloxane
surface active agents. Production requires as the principal inputs
a polysiloxane hydride fluid and polyalkylene oxide having terminal
unsaturation. Identification of the polysiloxane hydride fluid is
based on the following nomenclature:
T=methyltrisiloxy unit
D=dimethyldisiloxy unit
M=trimethylsiloxy unit
D.sup.1 =methylhydrogendisiloxy unit
The polysiloxane hydride fluids shown herein are produced by acid
equilibration of appropriate input materials. The molecular weight
and structure for the base polysiloxane hydride fluid is shown for
each surface active agent in Table I. The polyalkylene oxide having
terminal unsaturation is an allyl alcohol initiate polymerization
of ethylene oxide or a 50 by weight mixture of ethylene oxide with
propylene oxide. The final molecular weight and monomer input for
the polyalkylene oxide portion are indicated for each surface
active agent in Table I. The functional polyalkylene oxide was
diluted with toluene and azeotroped to eliminate water.
Subsequently a platinum catalyst was added along with a
stoichiometric amount of polysiloxane hydride fluid and the mixture
was heated to 100.degree. C. for 4 to 5 hours to insure complete
reaction. The toluene was stripped and the resultant polysiloxane
surface active agent was diluted to 10% by weight solution with
cyclic D.sub.4 and D.sub.5 silicone fluid.
TABLE I
__________________________________________________________________________
1 2 3 4 5 6
__________________________________________________________________________
Polysiloxane hydride 30,000 30,000 30,000 30,000 30,000 30,000
fluid Polysiloxane hydride MD.sub.400 D.sup.1 .sub.8.5M MD.sub.380
D.sup.1 .sub.28M MD.sub.400 D.sup.1 .sub.5.5M MD.sub.400 D.sup.1
.sub.18M TD.sub.400 D .sup.1 .sub.5.5 M.sub.3 TD.sub.400 D .sup.1
.sub.8M.sub.3 fluid, structure Polyalkylene oxide, MW 1,800 550
1,800 550 1,800 550 Ethylene Oxide/Propylene 50/50 100/0 50/50
100/0 50/50 100/0 Oxide, # Polysiloxane hydride 65/35 65/35 75/25
75/25 75/25 75/25 fluid/Polyalkylene Oxide weight
__________________________________________________________________________
EXAMPLES 1 THROUGH 6
Antiperspirant sticks were manufactured using each of surface
active agents in surfactants 1 through 6. Table II shows
compositions for Part A and Part B. Part A contains as the surface
active agent the corresponding surfactant 1 through 6. Part A is
heated to 57.degree. to 60.degree. C. until all wax is melted and
stirred to a homogeneous mixture. Likewise, Part B is heated to
57.degree. to 60.degree. C. Part B is added to Part A with
continued mixing, and the resultant water in oil emulsion is cooled
to just above melting. The emulsion is poured into commercially
available stick containers which have been cooled in an ice box.
Observations of each stick composition are noted in Table I.
TABLE II ______________________________________ 1 2 3 4 5 6
______________________________________ Part A Surfactant 1.0 1.0
1.0 1.0 1.0 1.0 D.sub.4 Fluid 9.0 9.0 9.0 9.0 9.0 9.0 D.sub.5 Fluid
15.0 15.0 15.0 15.0 15.0 15.0 Stearyl Alcohol 12.0 12.0 12.0 12.0
12.0 12.0 Methyl 3.0 3.0 3.0 3.0 3.0 3.0 Hydroxystearate Sorbitan
0.1 0.1 0.1 0.1 0.1 0.1 Mono-oleate Part B Aluminum 25.0 25.0 25.0
25.0 25.0 25.0 Zirconium Chloride Water 34.9 34.9 34.9 34.9 34.9
34.9 Observations Stick Hardness firm soft soft firm soft soft
Stick Leakage leak leak leak no leak leak leak w/use Stick Remelt
-- -- emulsion stable -- -- broken emulsion mixing restored does
not with restore mixing ______________________________________
* * * * *